16 ideas
| 3745 | Must sentences make statements to qualify for truth? [O'Connor] |
| Full Idea: Maybe a sentence is not a candidate for truth until it is used to make a statement. | |
| From: D.J. O'Connor (The Correspondence Theory of Truth [1975], Ch.6) |
| 3742 | Beliefs must match facts, but also words must match beliefs [O'Connor] |
| Full Idea: Our beliefs must claim a correspondence with facts, and then the verbal expression of the belief must correspond to the belief itself. | |
| From: D.J. O'Connor (The Correspondence Theory of Truth [1975], Ch.4) |
| 3744 | The semantic theory requires sentences as truth-bearers, not propositions [O'Connor] |
| Full Idea: The Semantic Theory of truth requires that sentences are truth-bearers (rather than statements, or propositions). | |
| From: D.J. O'Connor (The Correspondence Theory of Truth [1975], Ch.6) |
| 3749 | What does 'true in English' mean? [O'Connor] |
| Full Idea: We do not seem to have any use in ordinary discourse for phrases like 'true in English', 'false in German'. | |
| From: D.J. O'Connor (The Correspondence Theory of Truth [1975], II.1) |
| 11211 | If a sound conclusion comes from two errors that cancel out, the path of the argument must matter [Rumfitt] |
| Full Idea: If a designated conclusion follows from the premisses, but the argument involves two howlers which cancel each other out, then the moral is that the path an argument takes from premisses to conclusion does matter to its logical evaluation. | |
| From: Ian Rumfitt ("Yes" and "No" [2000], II) | |
| A reaction: The drift of this is that our view of logic should be a little closer to the reasoning of ordinary language, and we should rely a little less on purely formal accounts. |
| 3746 | Logic seems to work for unasserted sentences [O'Connor] |
| Full Idea: If sentences can have truth-values only when they occur as asserted, it would be impossible to have a truth-functional basis to logic. | |
| From: D.J. O'Connor (The Correspondence Theory of Truth [1975], Ch.6) |
| 11210 | Standardly 'and' and 'but' are held to have the same sense by having the same truth table [Rumfitt] |
| Full Idea: If 'and' and 'but' really are alike in sense, in what might that likeness consist? Some philosophers of classical logic will reply that they share a sense by virtue of sharing a truth table. | |
| From: Ian Rumfitt ("Yes" and "No" [2000]) | |
| A reaction: This is the standard view which Rumfitt sets out to challenge. |
| 11212 | The sense of a connective comes from primitively obvious rules of inference [Rumfitt] |
| Full Idea: A connective will possess the sense that it has by virtue of its competent users' finding certain rules of inference involving it to be primitively obvious. | |
| From: Ian Rumfitt ("Yes" and "No" [2000], III) | |
| A reaction: Rumfitt cites Peacocke as endorsing this view, which characterises the logical connectives by their rules of usage rather than by their pure semantic value. |
| 3747 | Events are fast changes which are of interest to us [O'Connor] |
| Full Idea: The standard cases of events are physical changes which happen sufficiently fast to be observed as changes, and which are of sufficient interest to us to be noticed or commented on. | |
| From: D.J. O'Connor (The Correspondence Theory of Truth [1975], Ch.7) |
| 13768 | Validity can preserve certainty in mathematics, but conditionals about contingents are another matter [Edgington] |
| Full Idea: If your interest in logic is confined to applications to mathematics or other a priori matters, it is fine for validity to preserve certainty, ..but if you use conditionals when arguing about contingent matters, then great caution will be required. | |
| From: Dorothy Edgington (Conditionals [2001], 17.2.1) |
| 13770 | There are many different conditional mental states, and different conditional speech acts [Edgington] |
| Full Idea: As well as conditional beliefs, there are conditional desires, hopes, fears etc. As well as conditional statements, there are conditional commands, questions, offers, promises, bets etc. | |
| From: Dorothy Edgington (Conditionals [2001], 17.3.4) |
| 13764 | Are conditionals truth-functional - do the truth values of A and B determine the truth value of 'If A, B'? [Edgington] |
| Full Idea: Are conditionals truth-functional - do the truth values of A and B determine the truth value of 'If A, B'? Are they non-truth-functional, like 'because' or 'before'? Do the values of A and B, in some cases, leave open the value of 'If A,B'? | |
| From: Dorothy Edgington (Conditionals [2001], 17.1) | |
| A reaction: I would say they are not truth-functional, because the 'if' asserts some further dependency relation that goes beyond the truth or falsity of A and B. Logical ifs, causal ifs, psychological ifs... The material conditional ⊃ is truth-functional. |
| 13765 | 'If A,B' must entail ¬(A & ¬B); otherwise we could have A true, B false, and If A,B true, invalidating modus ponens [Edgington] |
| Full Idea: If it were possible to have A true, B false, and If A,B true, it would be unsafe to infer B from A and If A,B: modus ponens would thus be invalid. Hence 'If A,B' must entail ¬(A & ¬B). | |
| From: Dorothy Edgington (Conditionals [2001], 17.1) | |
| A reaction: This is a firm defence of part of the truth-functional view of conditionals, and seems unassailable. The other parts of the truth table are open to question, though, if A is false, or they are both true. |
| 3743 | We can't contemplate our beliefs until we have expressed them [O'Connor] |
| Full Idea: It is only when beliefs are given some symbolic expression that they acquire the precision and stability that enables us to entertain them. | |
| From: D.J. O'Connor (The Correspondence Theory of Truth [1975], Ch.5) |
| 3748 | Without language our beliefs are particular and present [O'Connor] |
| Full Idea: Without language we would be restricted to particular beliefs about the here and now. | |
| From: D.J. O'Connor (The Correspondence Theory of Truth [1975], Ch.8) |
| 11214 | We learn 'not' along with affirmation, by learning to either affirm or deny a sentence [Rumfitt] |
| Full Idea: The standard view is that affirming not-A is more complex than affirming the atomic sentence A itself, with the latter determining its sense. But we could learn 'not' directly, by learning at once how to either affirm A or reject A. | |
| From: Ian Rumfitt ("Yes" and "No" [2000], IV) | |
| A reaction: [compressed] This seems fairly anti-Fregean in spirit, because it looks at the psychology of how we learn 'not' as a way of clarifying what we mean by it, rather than just looking at its logical behaviour (and thus giving it a secondary role). |